Ageing, or rather anti-ageing, is big, big business out here. Google, for example, has invested millions in CalicoLabs, the secretive R&D company ‘whose mission is to harness advanced technology to increase our understanding of the biology that controls lifespan’. Then there is Human Longevity Inc, the $70-million company founded by billionaire biologist/entrepreneur Craig Venter, the first person to sequence the human genome, whose mission involves employing stem cell therapy to extend human lifespan well into the hundreds.
Peter Thiel, meanwhile, co-founder of PayPal and the first ever investor in Facebook, has ploughed millions into the quest for immortality. It is he who supports the SENS Research Foundation, headed by Aubrey de Grey (de Grey being that eccentric, bearded Cambridge professor who sensationally claimed that the first person to live for a 1000 years had already been born). But, as Zadran tartly points out, they are all men. And none of them, it seems, gives a rat’s arse about hot flushes.
‘When I went to my chair at UCSF, and I told him that I wanted to do a study on menopausal nuns, because no one else was doing it, he actually laughed. Can you imagine the horror of that? He said, “This is one of the best scientific institutes in the country, and you want to study hot flashes? Why aren’t you doing MS or Parkinson’s?”’
The answer is that she is absolutely hell-bent on changing the way the world views the ageing woman. Even if not by the time she herself hits the menopause. ‘That’s what I tell my students… just to record what you can is important, and maybe 50 years from now someone else will take up the baton.’
The research that is already out there on vasomotor symptoms, i.e. hot flushes, is scant. What there is links them to both heart disease* and impaired ultimate cognitive outcome.† But Zadran thinks otherwise. Could they have the opposite effect? That is, the more hot flushes we have, the less likely we are a) to suffer heart disease and b) to go gaga. Hot flushes, she believes – how often we have them, when we have them, how long they last, what they feel like – may be the key to why women have better longevity than men.
‘Think of it this way,’ she says. ‘You’ve had all these dynamic hormones in your body for 50 years, the oestrogen, progesterone, testosterone, which are all critical for learning and memory, and all of a sudden those hormones aren’t there any more. What we think is happening is that the brain is having to adapt to the environment and one of the side effects of that adaptation are these hot flashes.
‘The more it has to adapt, the more efficient it becomes,’ she goes on, ‘a little like when you go abroad – the more you engage with the locals, the more you can live in that environment. It’s as if the brain is being put into a country with a language it doesn’t understand any more because there is no oestrogen or progesterone or testosterone; the way it relearns is to heat up the body, ergo hot flashes. Now, because the brain is the most important organ aside from the heart, other areas get skimped on, such as healthy bones and supple skin, hence vaginal dryness and osteoporosis – all in service to the brain.
‘The data so far is too preliminary to validate… but what we think is happening is that there is a degree of plasticity in the ageing female brain, and for me this is a piece of a puzzle, and the puzzle is: why do women live beyond the menopausal transition when it doesn’t make evolutionary sense, on a resource level, apart from anything else, that they should?’
* Amos Pines, University of Tel Aviv, 2011.
† http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2756983/
5
WHALES AND HUNTER-GATHERERS. AND JANE FONDA
Yes. Why do we make sense? Why do we ‘turn Catherine’s corner’ rather than keep on reproducing, or, like chimpanzees, simply curl up and die when we finally can’t? From an evolutionary point of view it is one of the biggest unanswered questions: are we to thank modern medicine and better living conditions for living so far beyond our fertile years? Doesn’t the fact that life expectancy for women in 1900 was 47 and by 2000 was nearer 80 make it all kind of obvious?
You would think, wouldn’t you? Intuitively, rationally, that’s got to be the answer. But then why do female killer whales become menopausal? To get more of a handle on the phenomenon of Orcinus orca granny, I make a visit one rainy afternoon to the University of Exeter. This is where Dr Darren Croft runs his lab at the Centre for Research in Animal Behaviour. Last summer he and his colleague Lauren Brent went to the north Pacific Ocean, just off the coast of Vancouver Island, to study the habits of killer whales in the wild. Young-seeming and delightfully woolly, with hair he keeps tucking behind his ears, 40-year-old Croft is a behavioural ecologist whose past work has involved the social networks of sharks, dairy cows and guppies. (Female guppies, he’ll have you know, evolved to swim faster than males in order to escape sexual harassment.)
Typically, female killer whales become mothers between the ages of 12 and 40. But, while males usually never make it to 50, the females often live for more than 90 years. Why? Croft and Brent wanted to know. When, thanks to us humans pilfering and polluting the seas, killer whales in the wild live in a more perilous environment, arguably, than ever before?
The answer, they believe, is information. Older female killer whales, with their old wives’ wisdom, are the ones which lead the rest of the pod to precious salmon stocks – the pod depends on her, and that very much includes her somewhat namby-pamby adult male offspring. Far from leaving home once they themselves mate, they stick next to their mummies for their entire lives (and if she dies – studies have shown – so, almost inevitably, do her adult sons). This, Croft explains, provides an insight into how the menopause evolved in humans – primitive societies, after all, didn’t write down what they learnt; they had to pass it down from generation to generation.
Which brings us to something called the Grandmother Hypothesis, a crucial evolutionary theory to get your head around if you ever thought, once you hit the menopause, you were redundant in any way.
An aside. I don’t know if you ever watched that reasonably amusing Netflix sitcom, Grace and Frankie, starring Jane Fonda and Lily Tomlin, about two older ladies becoming soul buddies after their husbands fall in love and decide to get married. There is this particular scene in one episode where the Lily Tomlin character is trying to get the checkout guy to pay attention to her rather than a cute young blonde so she can buy a pack of cigarettes. Well, you can imagine it. He acts like she is totally invisible and at a certain point Tomlin’s buddy, the Jane Fonda character, has a proper crazy-lady melt-down on her behalf. ‘Do you think it’s right to ignore us because we don’t look like her!’ she screams like a banshee as Tomlin wheels her out of the store.
It is preposterous and hammy and not that funny (although chapeau to Jane Fonda for looking so absolutely magnificently wonderful at 78. Who is her surgeon? I think we need to know). But I defy you, if you are the same age as me, not to relate. And the reason I mention it here is that it’s so easy to make that leap, to think that, because we cannot offer the world our sexuality, then ipso facto we must be ‘roadkill’. And here we have some pretty cold proof that we are not.
The idea that we have biologically adapted to the menopause, or ‘premature reproductive senescence’, and are not living beyond our fertile years simply as a by-product of better medicine and kinder living conditions, was first posited in 1957 by the evolutionary theorist George C. Williams. His then revolutionary theory was that the menopause, far from being a sign of decrepitude, was a positive evolutionary adaptation. His argument was that by helping to forage for food while her daughter was breastfeeding, providing wisdom and caring for her grandchildren, unencumbered by pregnancies or infants of her own, the older non-fertile female, i.e. the grandmother, increased the chance of passing her genes on to the next generation.
Which is where anthropologist Kristen Hawkes, a pioneer in the study of hunter-gatherer foraging strategies, comes in. In 1985 she and her team went out to study the Hadza tribe in northern Tanzania, one of the few surviving hunter-gatherer groups left in the w
orld besides the Ache in Uruguay and the !Kung in the Kalahari desert, and as such one of the last windows into the way we lived at the dawn of civilisation.
It was while observing the crucial role that older women played within the tribe in collecting food and caring for their grandchildren that she co-developed something called the Grandmother Hypothesis, that is: females have evolved to live beyond their reproductive years to help care for their daughters’ children and in doing so allow those daughters to wean their children earlier and therefore bear more offspring. In passing down their longevity genes to those children, human lifespan increased.
According to Hawkes, earlier weaning and longer childhood (as opposed to later weaning and shorter childhood in chimpanzees, our closest relatives) are what underlie subsequent important changes in human evolution, and these things couldn’t, she argues, have been effected without the role of grandmothering.
Grandmothering, according to the hypothesis Hawkes favours, provided the context to make us more dependent on each other socially, to engage more with each other, which in turn gave rise to ‘a whole array of social capacities that are then the foundation for the evolution of other distinctly human traits, including pair bonding [rather than mating with whoever when we are on heat, like chimpanzees], bigger brains, learning new skills and our tendency for cooperation.’*
‘If you are a chimpanzee infant, you don’t have to worry about your mother’s commitment – it’s your birthright to be your mother’s central concern until you are weaned,’ Hawkes explained to me on the phone from the University of Utah where she now holds a professorship. ‘But if there are overlapping independents [that is, other children to tend to besides you], you have to make more of an effort to be noticed. Being canny and cute and solicitous and needy [my italics] will make a huge difference to your survival.’
This hypothesis† has since been contested, but was given a big fat boost four years ago by a mathematical computer simulation which showed that, even with the weakest addition of grandmothering, ape-like life stories became human. Conversely, when the grandmothering input was taken out, those life stories stayed ape-like.
The implications of which are pretty huge. Could the menopause be the key to human consciousness? Without its existence might the human race not have evolved? Meanwhile, what must it have been like to be menopausal 1000 years ago? (And yes, if you made it through childbirth, there was a significant chance you would experience it). Was it better for us then, or worse? What did it feel like? And what does the role of the prehistoric woman d’un certain age tell us about civilisation now?
To find out, I’ve decided to put my camping phobia to one side and and go hang out for a few days with the Hadza myself.
Here I am, then, in Tanzania, bumping along a dirt track in the back of a Land Rover towards Mukengelko, one of the temporary Hadza settlements in the Yaeda Valley on the western side of Gideru Ridge. Numbering less than a thousand people, the Hadza or Hadzabe are a nomadic indigenous people, whose homelands are scattered around Lake Eyasi on the floor of the Central Rift Valley and the Serengeti Plains. Because of safari hunting and neighbouring tribes encroaching on their lands, game sources have dwindled considerably since Hawkes et al were out here, and they have had to supplement their diet with modern foodstuffs in order to survive. But there are still around 200–300 who live and subsist in almost exactly the same way we did thousands of years ago before agriculture was invented.
About 20 minutes’ drive from base, our guide Mika spots a Hadza couple he recognises, on the 15-kilometre walk from Domanga camp to Buluku. Because they are a nomadic tribe they have few material possessions and carry everything they own – bows, arrows, a few tools and maybe some berries picked earlier in the day – on their backs. It’s a lesson in de-cluttering one’s life, it really is. In fluent Swahili, Mika, who is the grandchild of missionaries and was brought up in the bush, offers them a ride and they both get into the back, looking with neither friendliness nor hostility at the two new white folk or ‘mzungus’ (myself and a photographer) in their midst.
Right from the get-go it is clear that Tausi, the wife, who has borne her husband five children, calls the shots. She has decided they are not going to get dropped off at Bukulu but are going to come all the way to Mukengelko with us in order to get some tobacco. Enthusiastically, I proffer a couple of packs of Camels that I bought in Duty Free having been told that, above almost everything else, the Hadza absolutely adore to smoke. Her husband takes them, but not with the effusive gratitude I confess I was expecting. See, what the Hadza love even more than tobacco is weed.
I ask Mika how old Tausi is – to me she looks my age, 55, maybe a bit younger were it not for her filmy eyes – but he doesn’t know and, more importantly, neither does she. With no calendars or clocks, why would she? But she guesses around 45. She’s done with having children; most Hadza women give birth to their last child in their forties. Probably because they eat less than European women, the median age for starting menopause among Hadza women is around 43.4 years compared to a median age of 49.6 for European women. Having made it to her forties, Tausi can easily expect to live into her mid-sixties and will probably survive much longer.‡ Statistically, her husband will die before her. Our guide tells us that many of the older Hadza men, less nimble on their feet, die falling out of baobab trees while foraging for honey. Placated with a small amount of weed, which she ties into a little knot in her kanga (reminding me of Marie Antoinette hiding her diamonds in her petticoats, in a way), Tausi sternly decides for the pair of them that they do not need to go to our camp, after all, and they both get out at Bukulu.
The following morning we are up at 5.45am when the air is cool and the sun is yet to rise: it is too hot to hunt or forage in the heat of the day. Historically, the Hadza have never experienced famine and do not see the point of rearing cattle or growing corn, which may or may not yield a return, depending on the weather and environment. In this sense, they are the ultimate example of living in the present, never hoarding, always believing that there will be enough to go round the following day. And in comparison to, say, the Masai, whose herdsmen in their traditional red robes we kept seeing on the road from Arusha, they seem downright modern.
Despite a deep-seated fear of insects, and a low to mid-level of panic that a hyena or honey badger would smell the protein bars at the bottom of my bag and find its way into my tent, I find I have slept well and dreamt cinematically. After drinking the delicious locally produced coffee out of plastic cups round the fire while watching dawn break, we embark on foot on the three-kilometre journey back to Bukulu, a mere leg-stretch to the average Hadza tribesperson who is used to walking 50 kilometres or more a day.
When we arrive, a group of women, including Tausi and Elena, a young-looking girl who is suckling a child, are sitting outside a hut shaped like an upside-down nest, constructed of twigs and long grass, its gaping holes plugged up with bits of cardboard and material. These are the temporary shelters the Hadza, with their exemplary invisible footprints, are known for, melting away to nothing when they move on. Despite the encroaching heat of the day, a fire has been lit and on its burning embers is a small bowl of murky-looking water, which Elena collected from our camp last night.
Aside from Tausi and Elena, there is Hadiya, a smiley, pretty woman married to Yasaneda (Hadza for ‘pothead’, hah). Then there is Herta, Elena’s mother, to whom the baby verging on toddler is constantly passed back and forth, the moment it struggles or utters the slightest whimper. Herta has three grandchildren in total and good-naturedly likens them to sacks of corn. Once they are partially weaned, she says, on her back they go. At no point does the toddler have reason to cry. How different to the lot of a Western baby who is left alone in his or her cot for hours courtesy of Gina Ford-style scheduled feeding, or plonked in a nursery before he or she can talk. There’s a link here, as to why there is no word for ‘depression’ in the Hadza language, I’m sure of it. In many ways, being the child of
a hunter-gatherer, or indeed any primitive society where children are treated a bit like backpacks, must be one of the most secure, confidence-building experiences in the world.
Like the couple yesterday, the women are not that fazed by our appearance on the scene. They are used to anthropologists studying their ways and the growing hordes of galumphing ethnotourists and National Geographic crews wanting to take their pictures.
The men, meanwhile, are gathered a couple of feet away and are doing what they do best, shooting the breeze while melting their spearheads in the fire to resharpen the tips; inhaling on their handmade stone pipes and cough cough coughing away as they take in the last remains of someone’s stash.
In many ways, the Hadza aren’t so unique. Chores are separated by sex. Men do the hunting, women do the gathering (the only animal Hadza women, by tradition, are allowed to hunt is the leopard tortoise). Women bitch, men boast, and when they’re bored of their wives they leave them for younger models.
Meanwhile, given the increasing unpredictability of game as a food source and the reliability of boring old tubers, it is the women’s work that in the end counts. ’Twas ever thus, sigh. Really it should be gatherer-hunter, not the other way round.
On the other hand, there is something uniquely egalitarian, uniquely socialist, actually, about the Hadza lifestyle. Everything, but everything, from weed to meat to baobab fruit must be shared (I offer, as a gift, some beads and necklaces I brought from home, and notice, the next day, some of them on the necks and wrists of members from other camps I’d not yet been to).
The overall vibe, meanwhile, is unusually non-sexist – when Hadza women marry into other ethnic groups, they often return because they dislike the way non-Hadza men treat them. Arranged marriages are not at all the norm and young girls are encouraged to ‘shop around’ before committing. If a husband strays too long in another camp, he is quite likely to come back and find that his wife has taken up with someone else. Another thing that becomes evident the longer I’m with them is that no young mother is expected to go it alone; and no infant, it seems, doesn’t have a grandmother around.
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